CORE A FSHD BIORESOURCES CORE No pathogenic gene(s) have been identified in FSHD and the molecular and cellular pathophysiology remains unclear. Moreover, the complex genetic and epigenetic changes have precluded the development of a representative animal model. Consequently, access to large numbers of well-characterized, patient-derived biological samples remains vital in advancing FSHD research. The overall aim of the proposed FSHD Bioresources Core is to generate wellcharacterized biological resources, collected in a standardized way and that will assist the Program Project's four proposed scientific studies achieve their proposed aims. To this end we will generate sets of biological resources from a) FSHDl subjects, b) FSHD2 (phenotypic) subjects and c) normal control subjects. Each set will include a flash-frozen muscle sample, a myoblast cell line and a skin-derived fibroblast cell line. Each subject will be comprehensively genotyped for the FSHD region and clinically characterized for overall disease severity, strength of the muscle group from which the sample is derived as well as pathologic grading of an adjacent muscle biopsy sample.